I am more on the software side, so maybe a bit biased. In addition I am not very much interested in SUPER-versions of our old computers, but more on making modern replacements with extras to make life easier

I'd say please make it compatible with our old Orics. Make it so it could work as a Telestrat, an Oric-1, an Atmos or a Pravetz. Make it so it is easy to test different ROMs, and:
- Some interface which makes it possible to read disk images from an SD (imho much better than CF, but that is just me).
- Some way of loading (fast if possible) tap image files stored in an SD too!
- Some modern way to connect to a TV
- Keep the expansion port to test and use our old hardware
- Make it so it can fit inside an Oric case.

To me, the "great" Oric would be close to what Chema explains: standard all-in-one Oric
- Oric-1, Atmos, Telestrat, Pravetz (Nova64?)
- with all possible existing extensions: light pen, all disk controllers, one 3" drive, one 3.5 drive, one 5.1/4 drive, one SD card drive, tape load, vocal synthseizers, Joystick ports, RS232...
- easy way to plug to any screen

Ok, would be complicated but this would allow:
- to use all old sofwtare whatever the media it uses (having a SD car only Oric will prevent you from reading your good old 3" disks !)
- to make software without wondering "how may Oric users have a Joystick", "how many have a RS232 card", ...
- the extensions would be standard, no need to wonder "which joystick interface can they have"

Anything else making Orics faster, with better resolution, colors or whatever are not on my top priority as it would not really be our good old Oric anymore. It's an old debate, but building a different hardware equals making a new comptuer, and if so... One could wonder: why not directly work on Mac or PC or Raspberry
(on the other hand, having the choice of setting the 8 colors among 4096 is tempting, as well as having a pixel by colour... Argh )

I liked the Commodore 128 which has some advanced features but still had a C64 inside, so you could switch to the C64 mode for compatibility with its software.

The Telestrat was a nice idea of a similar kind but not advanced enough IMHO.

The colours on the C64 give a lot of options, orange and different greys open up what can be done. The Oric screen was odd having the 6*8 pixel cells.
The Oric had different screen modes. I would add some more so that you could have 8*8 cells and more colours. Sprites would be nice too.

The C64 sound was a big step up too allowing sounds from different waveforms. These days there's so many MIDI files it'd be nice to have the ability to plug in a Soundblaster compatible card and have something to drive it.

The Einstein computer booted with no BASIC loading. If you wanted BASIC that had to be loaded from disk. We could do that or have a cartridge - but I wonder if we could have a version of C for the Oric with compiler.

All this would need extra memory and it'd need to run faster so the CPU etc would need upgrading.

Failing all this it'd be nice to turn a Atari ST into an Oric. The hardware is good but it doesn't have Oric BASIC or Sedoric etc.

All of Chema, Symoon & Steve request are what are planned for my StratoCumulus/NewOric project, 100% compatible with an oric with a few addition (like the color palette per region demo I've made earlier: here: https://www.youtube.com/watch?v=kp5pDU7AyhU )

But the main goal is still to keep 100% compatibility with a normal oric 1/Atmos, something that use the new feature would run without a problem on a normal 1/Atmos.

Faster CPU will be a problem, as the ULA expect really strict timings on the 6502 memory bus. Making a device with a faster CPU may create an incompatible device (and we can't take emulators as an exemple of 'look it works with Oricutron'.
There are contrains on hardware that does not exist on software

One "out there" idea I had, was the idea of putting an array of Oric's into an FPGA and wiring them up somehow with networking - but still they are regular old, well-synthesized Oric's, i.e. emulations of our original hardware, warts and all, albeit .. you've got 16 of them, and they can communicate on-array over some kind of buss.

I admit, that the reason for this out there idea in my head was the concept of having a multi-timbral array of Oric synthesizers that could be used to make wicked music .. but since I'm yet to get even the 8 real Atmos' I've got for this project actually set up and working in the real world, this is still just an out there idea. (Mostly, its MIDI. If I had MIDI, I'd have an 8-voice Atmos synth-bank in my studio, on its own little rack..)

So this is why I keep coming back to MIDI as a subject, since it allows very rudimentary - yet effective - networking between Orics, without breaking any performance rules or introducing huge RAM consumption to be able to get packets in/out..

But then the idea transmogrifies: what if we do indeed have an array of 16 Orics (arbitrary #), and a couple of them are assigned to MIDI switch duties, maybe one is assigned to color-LUT's, and another does some kind of mixing/muxing, so that we can get interlaced higher-resolution modes (this is all a pipe dream) by using some Oric's as accelerators for the 'front-end Oric' which runs a user program.